It’s a Product Patent… It’s a Process Patent… It’s Product-by-Process Patent!

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In a significant development, the Delhi High Court on July 24, 2023 passed a detailed order on ‘product-by-process’ patent claims in Vifor International Ltd. v. MSN Laboratories Pvt. Ltd and anr. With this order the court disposed of different interim applications filed in 4 suits (three suits were filed by Vifor and Emcure against MSN Labs, Dr. Reddy Labs and Corona Remedies Pvt. Ltd. and the fourth one was filed by Virchow Biotech against Vifor), and refused to grant an interim injunction to Vifor International Ltd and Emcure Pharma Ltd. (Plaintiffs). The Court held that the variants of Ferric Carboxymaltose (FCM) do not prima facie infringe the plaintiff’s patent and allowed the defendants to launch their versions of the drug.

There have been previous orders that have mentioned product-by-process claims (for eg. Nippon A&L Inc v. Controller of Patents, analysed by Amit here and here and the IPAB order in the State University of New York v. Asst. Controller of Patents (I wasn’t able to find an openly accessible version of this order) but these have not discussed the acceptability of such claims within the Indian patent regime. The present case is perhaps the first where the court deconstructs the question of patentability and infringement of product-by-process patent claims in India. For this the court has relied on the Guidelines for Examination of Patent Application in the Field of Pharmaceuticals to establish that India accepts such claims and a plethora of foreign decisions with persuasive value, to frame a conceptual understanding of these types of claims.

But first, just to take a step back:

What is a Product-by-Process Patent Claim?

As a part of the patent bargain, an inventor must describe the invention and disclose the best method to perform it. But there may be instances where owing to the challenges in describing the physical or structural characteristics of the invention, disclosing the invention within the claims becomes a tedious task. This can later invite trouble in getting the patent registered after the examination, and further during the infringement proceedings. To resolve this predicament, an inventor files a specification with claims disclosing the product and the process to manufacture the product. But what is the scope of protection in such a case? Is it limited to only the end product regardless of the disclosed method/ process?

Let’s have a quick look at the practices of other countries. In the US, as explained in the USPTO Manual of Patent Examining Procedures, a product-by-process claim would include only the products made after following the recited method/ process, and the patentability of such claims is subjected to the patentability of the product claimed. As per the EU’s Guidelines for Examination, the invention lies “not in the process per se but in the technical properties imparted to the product by the process.” This is explained by Christian Rupp here (paywalled), to mean any product having “fingerprints” of the specified process. EPO’s Technical Board of Appeal’s 1984 decision in International Flavors and Fragrances Inc further clarified that such claims are to be used only in when the product cannot be satisfactorily defined.

Interestingly, in the Patent Examination Manual of the New Zealand IP Office, earlier the emphasis was given to the novelty of the process, however, after its 2013 Patent Act, the novelty of the claimed product obtained by the claimed process will be tested against the anvils of the existing prior art. Explaining the approach of Brazilian courts and patent office (BRPTO), Roberto Rodrigues Pinho et. al, here, have mentioned that while examining the patentability of a claim, the BRPTO focuses on the novelty and non-obviousness of the resulting product, regardless of the process and sets the condition that the product cannot be described otherwise, without the process.

Patentability of Product-by-Process Claim in India

The plaintiff argued that the Indian patent regime does not recognize product-by-process claims and instead divides the claims either into a product claim or a process claim. The court, however, rejected this understanding and relying on the Guidelines for Examination of Patent Application in the Field of Pharmaceuticals and the IPAB order in the State University of New York case, it held that such claims have been incorporated within the Indian patent system. Discussing the patentability of the claims, the court then clarified that the patentability of product-by-process claims depends on the novelty and non-obviousness of the product, regardless the process used to describe it.

The court then relied on the House of Lords decision in Kirin-Amgen v. Hoechst Marion Roussel Ltd. to interpret product-by-process patent claims within Section 48 (b) and clarified that the provision is pari materia (“dealing with the same subject matter”) to Article 64 (2) of the European Patent Convention (EPC). Section 48 (b) of the Patent Act grants the right to prevent unauthorized use of a process patent which includes the right to restrain the use, sale, import of the product obtained directly by that process in India. Article 64(2) of the EPC states that if a subject matter is a process, then the patent protection shall be extended to products directly obtained by such process. The Key phrase in both provisions is “products directly obtained by the process.” Relying on this, the House of Lords in Kirin-Amgen held that this provision removes the practical argument for allowing product-by-process patent claims, and now a patentee claiming infringement of its product derived directly from a process must rely on its process claim and Article 64(2).

However, I am not sure how the Kirin-Amgen is useful in importing product-by-process claims in the Indian Patents Act. The decision restricts the scope of ‘product-by-process’ claims and instead clarifies that owing to Article 64(2) the earlier, broader, protection is now limited to only products obtained directly by that process.

Assessment of the Suit Patent’s Claims by the Court

The plaintiff in claim no. 1 has claimed “water soluble iron carbohydrate complexes obtainable from an aqueous solution of iron (III) salt and an aqueous solution of the oxidation product of one or more maltodextrins using an aqueous hypochlorite solution at a pH-value within the alkaline range….”. In claim no. 2, a process for producing the above iron carbohydrate complex was claimed, “wherein one or more maltodextrins are oxidized in an aqueous solution at an alkaline pH-value using an aqueous hypochlorite solution and the obtained solution is reacted with an aqueous solution of an iron (III) salt.”

The plaintiffs argued that the suit claims for water-soluble iron carbohydrate complexes were product patent and that the expression “obtainable from” in Claim 1 highlights that the process claims are in fact only one of the many ways through which the FCM can be produced. The court, however, negated this as an inconsequential treatment of the process claims and held that the process is a characteristic property that distinguishes the plaintiff’s FCM from prior art. The court first assessed the complete specification of the suit patent and substantiated its finding by relying on the Plaintiff’s earlier stances during the patent prosecution stage, in opposition filed against applications of various third parties, and in response filed in EP application, where the plaintiff emphasized on the novelty of the process to obtain its iron carbohydrate complexes.

Criteria to Assess Infringement of Product-by-Process Claims

Once it determined that the suit patent claims are product-by-process patent claims, the court assessed whether they were infringed by the defendants or not. And this is where things get generally tricky regarding these ‘product-by-process’ claims. To determine infringement, the court assesses whether the allegedly infringing product is obtained by following the same process or not, and if the product is obtained by using a different process, then there is no case for infringement. This deference to the process claims, during infringement assessment, is made because without the limitations set therein, it would have been very difficult to identify the product. (see Abbot v. Sandoz)

Based on this, the court compared the processes of the parties and held that the process used by Corona Remedies is different from the process used by Vifor as it uses starch hydrolysate as the starting material for reaction, with Dextrose Equivalent (DE) value greater than 20, whereas, Vifor uses maltodextrin with DE value less than 20. Regarding the process used by Dr. Reddy’s and MSN, the court held that since their process uses ‘Oxone’ as an oxidizing agent instead of ‘aqueous hypochlorite’ solution as used by Vifor, their process is different than the suit patent and thus, found the same to be non infringing.


The order is pretty exhaustive and has tried to explain the concept of product-by-process claims with authoritative vigor. However, the biggest issue with the order is that it’s unclear how the product-by-process patent claims are accommodated within the scheme of the Indian Patents Act. While the IPO guidelines do explain these claims in para 7.9, they are persuasive and are not substantive/ authoritative provisions clarifying when resorting to such claims will be acceptable. Thus, the order should have been clear on how these claims are incorporated within the scheme of the statute.

The order also highlights the importance of the patent prosecution process in infringement proceedings as the court held the plaintiff accountable for their stance not only in their applications but also oppositions filed against other third-party applicants. This is a refreshing development, especially in light of the contrasting treatment towards the stance taken during Trademark prosecution stage. It’s also perhaps one of the rare instances where the court properly assessed the three factors of interim injunction instead of just granting an injunction in light of previous injunction orders. Interestingly, when the argument for an injunction order considering the trend of favorable orders in favor of the patent was raised by the plaintiff, the court quickly highlighted that in those orders the patent was expressly declared to be granted on ‘product-by-process’ claims, unlike what was argued by the plaintiff in this matter.

But perhaps the biggest takeaway of the order is that it throws light on a concept that has relatively remained alien to the Indian patent regime. While the court has made an attempt to lay the groundwork for the future, it somewhat missed the bus in setting a limit on when such claims should be accepted, as done in Brazil and EU. Though this could have been a deliberate move, considering that the order was passed in an application seeking an interim injunction or because this exercise should have been carried out by the Parliament, doing so would have ensured that such claims are expressly treated as exceptions and do not become new norms. But realistically speaking, I doubt that this order will inspire any applicant to willfully disclose their invention using ‘product-by-process’ claims owing to the oscillating considerations to the ‘product patent’ aspect of the invention while examining the claims first, and then later investigating the allegations of infringement considering the invention to be a process.

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